Inches of Hair Growth in a Month

Hair grows about half an inch every 30 days.

A person's hair grows in a cycle of new hairs being grown, hairs resting in a dormant stage and then hairs being shed. In normal conditions, this cycle remains constant and hair grows at a steady rate.

Hair Growth

The average person has about 90 percent of her scalp hair growing at all times. Each hair that is in a growing stage grows an average of half an inch every month, according to the American Academy of Dermatology.

Changes

Hairs that are in a resting stage will remain dormant for about two or three months before being shed. During this stage, those hairs do not grow.

Considerations

A person's rate of hair growth will gradually slow down over time, decreasing as he ages. Hormonal disorders, fungal infection and other disorders can interfere with the normal rates and cycles of hair growth, according to Family Doctor.org.

References

• American Academy of Dermatology: Hair Loss
• Family Doctor: Hair Loss and Its Causes